This invention relates to tires for vehicles which generally have at least one wheel at each corner such as passenger cars, vans, trucks or buses.
In common with most other types of tires, in order for this tire to perform well under all conditions it is usual for the ground contacting tread region of the tire to be provided with relatively deep grooves in the surface.
In wet conditions such grooves assist in clearing water from the contact area between the tire tread and the road surface and thus help to retain steering control of the vehicle by preventing aquaplaning. In other conditions such as snow and ice or in off-road applications such grooves provide edges which assist in the transmission of traction forces.
However the provision of such grooves effectively weakens the tire tread and renders it more prone to wear. This occurs because such grooves divide the tread into discrete elements such as ribs and blocks which individually are more susceptible to deformation and movement in the tire/ground contact region due to the tractive forces transmitted therein resulting in abrasion of the rubber against the road surface.
In making the present invention, the inventors studied the alignment of the grooves in the tread of such tires and determined that it was possible to arrange these so as to minimize wear of the tread rubber.